/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.myfaces.tobago.renderkit;

import org.apache.myfaces.tobago.component.ClientBehaviors;
import org.apache.myfaces.tobago.component.Facets;
import org.apache.myfaces.tobago.component.RendererTypes;
import org.apache.myfaces.tobago.component.Tags;
import org.apache.myfaces.tobago.component.Visual;
import org.apache.myfaces.tobago.context.Markup;
import org.apache.myfaces.tobago.context.TobagoContext;
import org.apache.myfaces.tobago.internal.behavior.EventBehavior;
import org.apache.myfaces.tobago.internal.component.AbstractUICommand;
import org.apache.myfaces.tobago.internal.component.AbstractUIEvent;
import org.apache.myfaces.tobago.internal.component.AbstractUIReload;
import org.apache.myfaces.tobago.internal.component.AbstractUIStyle;
import org.apache.myfaces.tobago.internal.renderkit.Collapse;
import org.apache.myfaces.tobago.internal.renderkit.Command;
import org.apache.myfaces.tobago.internal.renderkit.CommandMap;
import org.apache.myfaces.tobago.internal.renderkit.renderer.TobagoClientBehaviorRenderer;
import org.apache.myfaces.tobago.internal.util.ArrayUtils;
import org.apache.myfaces.tobago.internal.util.HtmlRendererUtils;
import org.apache.myfaces.tobago.internal.util.RenderUtils;
import org.apache.myfaces.tobago.internal.util.StringUtils;
import org.apache.myfaces.tobago.internal.util.StyleRenderUtils;
import org.apache.myfaces.tobago.internal.webapp.TobagoResponseWriterWrapper;
import org.apache.myfaces.tobago.renderkit.css.TobagoClass;
import org.apache.myfaces.tobago.renderkit.html.CustomAttributes;
import org.apache.myfaces.tobago.renderkit.html.HtmlAttributes;
import org.apache.myfaces.tobago.renderkit.html.HtmlElements;
import org.apache.myfaces.tobago.util.ComponentUtils;
import org.apache.myfaces.tobago.webapp.TobagoResponseWriter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.el.ValueExpression;
import javax.faces.component.EditableValueHolder;
import javax.faces.component.UIComponent;
import javax.faces.component.UIInput;
import javax.faces.component.ValueHolder;
import javax.faces.component.behavior.AjaxBehavior;
import javax.faces.component.behavior.ClientBehavior;
import javax.faces.component.behavior.ClientBehaviorBase;
import javax.faces.component.behavior.ClientBehaviorContext;
import javax.faces.component.behavior.ClientBehaviorHolder;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;
import javax.faces.convert.Converter;
import javax.faces.convert.ConverterException;
import javax.faces.model.SelectItem;
import javax.faces.model.SelectItemGroup;
import javax.faces.render.ClientBehaviorRenderer;
import javax.faces.render.Renderer;
import java.io.IOException;
import java.lang.invoke.MethodHandles;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

public abstract class RendererBase<T extends UIComponent> extends Renderer {

  private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

  private static final String FOCUS_KEY = HtmlRendererUtils.class.getName() + ".FocusId";

  // begin of "redefine" the method signatur (generics): UIComponent -> T

  @Override
  public final void encodeBegin(FacesContext context, UIComponent component) throws IOException {
    this.encodeBeginInternal(context, (T) component);
  }

  public void encodeBeginInternal(FacesContext context, T component) throws IOException {
    super.encodeBegin(context, component);
  }

  @Override
  public final void encodeChildren(FacesContext context, UIComponent component) throws IOException {
    this.encodeChildrenInternal(context, (T) component);
  }

  public void encodeChildrenInternal(FacesContext context, T component) throws IOException {
    super.encodeChildren(context, component);
  }

  @Override
  public final void encodeEnd(FacesContext context, UIComponent component) throws IOException {
    this.encodeEndInternal(context, (T) component);
  }

  public void encodeEndInternal(FacesContext context, T component) throws IOException {
    super.encodeEnd(context, component);
  }

  @Override
  public final void decode(FacesContext context, UIComponent component) {
    this.decodeInternal(context, (T) component);
  }

  public void decodeInternal(FacesContext context, T component) {
    super.decode(context, component);
  }

  @Override
  public Object getConvertedValue(
      final FacesContext facesContext, final UIComponent component, final Object submittedValue)
      throws ConverterException {
    return getConvertedValueInternal(facesContext, (T) component, submittedValue);
  }

  public Object getConvertedValueInternal(
      final FacesContext context, final T component, final Object submittedValue)
      throws ConverterException {
    if (!(submittedValue instanceof String)) {
      return submittedValue;
    }
    final Converter converter = getConverter(context, component, submittedValue);
    if (converter != null) {
      return converter.getAsObject(context, component, (String) submittedValue);
    } else {
      return submittedValue;
    }
  }

// end of "redefine"

  protected String getCurrentValue(final FacesContext facesContext, final T component) {

    if (component instanceof ValueHolder) {
      final ValueHolder valueHolder = (ValueHolder) component;
      if (valueHolder instanceof EditableValueHolder) {
        final EditableValueHolder editableValueHolder = (EditableValueHolder) component;
        final Object submittedValue = editableValueHolder.getSubmittedValue();
        if (submittedValue != null || !editableValueHolder.isValid()) {
          return (String) submittedValue;
        }
      }
      String currentValue = null;
      final Object result = ((ValueHolder) component).getValue();
      if (result != null) {
        currentValue = getFormattedValue(facesContext, component, result);
      }
      return currentValue;
    } else {
      return null;
    }
  }

  public static void renderFocus(
      final String clientId, final boolean focus, final boolean error, final FacesContext facesContext,
      final TobagoResponseWriter writer) throws IOException {
    final Map<String, Object> requestMap = facesContext.getExternalContext().getRequestMap();
    if (!requestMap.containsKey(FOCUS_KEY)
        && (clientId.equals(TobagoContext.getInstance(facesContext).getFocusId()) || focus || error)) {
      requestMap.put(FOCUS_KEY, Boolean.TRUE);
      writer.writeAttribute(HtmlAttributes.AUTOFOCUS, true);
    }
  }

  protected TobagoResponseWriter getResponseWriter(final FacesContext facesContext) {
    final ResponseWriter writer = facesContext.getResponseWriter();
    if (writer instanceof TobagoResponseWriter) {
      return (TobagoResponseWriter) writer;
    } else {
      return new TobagoResponseWriterWrapper(writer);
    }
  }

  protected void insideBegin(final FacesContext facesContext, final HtmlElements inside) {
    insideBegin(facesContext, (Object) inside);
  }

  protected void insideEnd(final FacesContext facesContext, final HtmlElements inside) {
    insideEnd(facesContext, (Object) inside);
  }

  protected boolean isInside(final FacesContext facesContext, final HtmlElements inside) {
    return isInside(facesContext, (Object) inside);
  }

  protected void insideBegin(final FacesContext facesContext, final Facets inside) {
    insideBegin(facesContext, (Object) inside);
  }

  protected void insideEnd(final FacesContext facesContext, final Facets inside) {
    insideEnd(facesContext, (Object) inside);
  }

  protected boolean isInside(final FacesContext facesContext, final Facets inside) {
    return isInside(facesContext, (Object) inside);
  }

  private void insideBegin(final FacesContext facesContext, final Object inside) {
    Integer insideCount = (Integer) facesContext.getAttributes().get(inside);
    if (insideCount == null) {
      insideCount = 0;
    }
    facesContext.getAttributes().put(inside, ++insideCount);
  }

  private void insideEnd(final FacesContext facesContext, final Object inside) {
    Integer insideCount = (Integer) facesContext.getAttributes().get(inside);
    if (insideCount != null) {
      insideCount--;

      if (insideCount > 0) {
        facesContext.getAttributes().put(inside, insideCount);
      } else {
        facesContext.getAttributes().remove(inside);
      }
    }
  }

  private boolean isInside(final FacesContext facesContext, final Object inside) {
    return facesContext.getAttributes().get(inside) != null;
  }

  /**
   * Special implementation for the reload facet (e.g. for tc:panel and tc:sheet).
   */
  public void encodeReload(FacesContext facesContext, AbstractUIReload reload) throws IOException {
    final TobagoResponseWriter writer = getResponseWriter(facesContext);
    writer.write("{\"reload\":{\"frequency\":" + reload.getFrequency() + "}}");
  }

  /**
   * Renders the tobago-behavior tag.
   *
   * @since 5.0
   */
  protected void encodeBehavior(
      final TobagoResponseWriter writer, final FacesContext facesContext, final ClientBehaviorHolder holder)
      throws IOException {
    if (holder != null) {
      final CommandMap behaviorCommands = getBehaviorCommands(facesContext, holder);
      encodeBehavior(writer, behaviorCommands);
    }
  }

  /**
   * Renders the tobago-behavior tag.
   *
   * @since 5.0
   */
  protected void encodeBehavior(
      final TobagoResponseWriter writer, final CommandMap behaviorCommands)
      throws IOException {
    if (behaviorCommands != null) {
      final Command click = behaviorCommands.getClick();
      if (click != null) {
        encodeBehavior(writer, ClientBehaviors.click, click);
      }
      final Map<ClientBehaviors, Command> other = behaviorCommands.getOther();
      if (other != null) {
        for (Map.Entry<ClientBehaviors, Command> entry : other.entrySet()) {
          encodeBehavior(writer, entry.getKey(), entry.getValue());
        }
      }
    }
  }

  private void encodeBehavior(
      final TobagoResponseWriter writer, final ClientBehaviors behaviors, final Command command)
      throws IOException {
    writer.startElement(HtmlElements.TOBAGO_BEHAVIOR);
    writer.writeAttribute(CustomAttributes.EVENT, behaviors.getJsEvent(), false);
    writer.writeAttribute(CustomAttributes.STOP_PROPAGATION,
        command.getStopPropagation() != null && command.getStopPropagation());
    writer.writeAttribute(CustomAttributes.CLIENT_ID, command.getClientId(), false);
    if (StringUtils.notEquals(command.getClientId(), command.getFieldId())) {
      writer.writeAttribute(CustomAttributes.FIELD_ID, command.getFieldId(), false);
    }
    writer.writeAttribute(CustomAttributes.EXECUTE, command.getExecute(), false);
    writer.writeAttribute(CustomAttributes.RENDER, command.getRender(), false);
    writer.writeAttribute(CustomAttributes.OMIT, command.getOmit());
    writer.writeAttribute(CustomAttributes.CONFIRMATION, command.getConfirmation(), true);
    writer.writeAttribute(CustomAttributes.DECOUPLED,
        command.getTransition() != null && !command.getTransition());
    final Collapse collapse = command.getCollapse();
    if (collapse != null) {
      writer.writeAttribute(CustomAttributes.COLLAPSE_OPERATION, collapse.getOperation().name(), false);
      writer.writeAttribute(CustomAttributes.COLLAPSE_TARGET, collapse.getFor(), false);
    }
    writer.writeAttribute(CustomAttributes.DELAY, command.getDelay());
    writer.writeAttribute(HtmlAttributes.TARGET, command.getTarget(), true);

    final Boolean resetValues = command.getResetValues();

    if (resetValues != null && resetValues) {
      writer.writeAttribute(CustomAttributes.RESET_VALUES, resetValues);
    }
    // todo: all the other attributes
    writer.endElement(HtmlElements.TOBAGO_BEHAVIOR);
  }

  protected CommandMap getBehaviorCommands(
      final FacesContext facesContext, final ClientBehaviorHolder clientBehaviorHolder) {
    CommandMap commandMap = null;

    for (final Map.Entry<String, List<ClientBehavior>> entry : clientBehaviorHolder.getClientBehaviors().entrySet()) {
      final String eventName = entry.getKey();
      final ClientBehaviorContext clientBehaviorContext
          = getClientBehaviorContext(facesContext, clientBehaviorHolder, eventName);

      for (final ClientBehavior clientBehavior : entry.getValue()) {
        if (clientBehavior instanceof EventBehavior) {
          final EventBehavior eventBehavior = (EventBehavior) clientBehavior;
          final AbstractUIEvent abstractUIEvent
              = RenderUtils.getAbstractUIEvent((UIComponent) clientBehaviorHolder, eventBehavior);

          if (abstractUIEvent != null && abstractUIEvent.isRendered() && !abstractUIEvent.isDisabled()) {
            for (List<ClientBehavior> children : abstractUIEvent.getClientBehaviors().values()) {
              for (ClientBehavior child : children) {
                final CommandMap childMap = getCommandMap(facesContext, clientBehaviorContext, child);
                commandMap = CommandMap.merge(commandMap, childMap);
              }
            }
          }
        }

        final CommandMap map = getCommandMap(facesContext, clientBehaviorContext, clientBehavior);
        commandMap = CommandMap.merge(commandMap, map);
      }
    }

    // if there is no explicit behavior (with f:ajax or tc:event), use the command properties as default.
    if ((commandMap == null || commandMap.isEmpty()) && clientBehaviorHolder instanceof AbstractUICommand) {
      if (commandMap == null) {
        commandMap = new CommandMap();
      }
      final AbstractUICommand holder = (AbstractUICommand) clientBehaviorHolder;
      commandMap.addCommand(ClientBehaviors.click, new Command(
          holder.getClientId(facesContext),
          holder.getFieldId(facesContext),
          holder.isTransition(),
          holder.getTarget(),
          null,
          null,
          ComponentUtils.getConfirmation(holder),
          null,
          TobagoClientBehaviorRenderer.createCollapsible(facesContext, holder),
          holder.isOmit(),
          null));
    }

    return commandMap;
  }

  private static ClientBehaviorContext getClientBehaviorContext(
      final FacesContext facesContext, final ClientBehaviorHolder clientBehaviorHolder, final String eventName) {
    final UIComponent component = (UIComponent) clientBehaviorHolder;
    return ClientBehaviorContext.createClientBehaviorContext(facesContext, component, eventName,
        component.getClientId(facesContext), null);
  }

  private static CommandMap getCommandMap(
      final FacesContext facesContext, final ClientBehaviorContext clientBehaviorContext,
      final ClientBehavior clientBehavior) {
    if (clientBehavior instanceof ClientBehaviorBase) {
      String type = ((ClientBehaviorBase) clientBehavior).getRendererType();

      // this is to use a different renderer for Tobago components and other components.
      if (type.equals(AjaxBehavior.BEHAVIOR_ID)) {
        type = "org.apache.myfaces.tobago.behavior.Ajax";
      }
      final ClientBehaviorRenderer renderer = facesContext.getRenderKit().getClientBehaviorRenderer(type);
      final String dummy = renderer.getScript(clientBehaviorContext, clientBehavior);
      if (dummy != null) {
        return CommandMap.restoreCommandMap(facesContext);
      }
    } else {
      LOG.warn("Ignoring: '{}'", clientBehavior);
    }
    return null;
  }

  protected void decodeClientBehaviors(final FacesContext facesContext, final T component) {
    if (component instanceof ClientBehaviorHolder) {
      final ClientBehaviorHolder clientBehaviorHolder = (ClientBehaviorHolder) component;
      final Map<String, List<ClientBehavior>> clientBehaviors = clientBehaviorHolder.getClientBehaviors();
      if (clientBehaviors != null && !clientBehaviors.isEmpty()) {
        final Map<String, String> paramMap = facesContext.getExternalContext().getRequestParameterMap();
        final String behaviorEventName = paramMap.get("javax.faces.behavior.event");
        if (behaviorEventName != null) {
          final List<ClientBehavior> clientBehaviorList = clientBehaviors.get(behaviorEventName);
          if (clientBehaviorList != null && !clientBehaviorList.isEmpty()) {
            final String clientId = paramMap.get("javax.faces.source");
            if (component.getClientId(facesContext).equals(clientId)) {
              for (final ClientBehavior clientBehavior : clientBehaviorList) {
                clientBehavior.decode(facesContext, component);
              }
            }
          }
        }
      }
    }
  }

  protected void renderSelectItems(
      final UIInput component, final TobagoClass optionClass,
      final Iterable<SelectItem> items, final Object[] values, final String[] submittedValues,
      final TobagoResponseWriter writer, final FacesContext facesContext) throws IOException {
    renderSelectItems(component, optionClass, items, values, submittedValues, null, writer, facesContext);
  }

  protected void renderSelectItems(
      final UIInput component, final TobagoClass optionClass,
      final Iterable<SelectItem> items, final Object value, final String submittedValue,
      final TobagoResponseWriter writer, final FacesContext facesContext) throws IOException {
    renderSelectItems(component, optionClass, items, value != null ? new Object[]{value} : null,
        submittedValue != null ? new String[]{submittedValue} : null, null, writer, facesContext);
  }

  protected void renderSelectItems(
      final UIInput component, final TobagoClass optionClass,
      final Iterable<SelectItem> items, final Object[] values, final String[] submittedValues,
      final Boolean onlySelected, final TobagoResponseWriter writer, final FacesContext facesContext)
      throws IOException {

    if (LOG.isDebugEnabled()) {
      LOG.debug("component id = '{}'", component.getId());
      LOG.debug("values = '{}'", Arrays.toString(values));
      LOG.debug("submittedValues = '{}'", Arrays.toString(submittedValues));
    }
    for (final SelectItem item : items) {
      if (item instanceof SelectItemGroup) {
        writer.startElement(HtmlElements.OPTGROUP);
        writer.writeAttribute(HtmlAttributes.LABEL, item.getLabel(), true);
        if (item.isDisabled()) {
          writer.writeAttribute(HtmlAttributes.DISABLED, true);
        }
        final SelectItem[] selectItems = ((SelectItemGroup) item).getSelectItems();
        renderSelectItems(component, optionClass, Arrays.asList(selectItems), values, submittedValues,
            onlySelected, writer, facesContext);
        writer.endElement(HtmlElements.OPTGROUP);
      } else {
        Object itemValue = item.getValue();
        // when using selectItem tag with a literal value: use the converted value
        if (itemValue instanceof String && values != null && values.length > 0 && !(values[0] instanceof String)) {
          itemValue = ComponentUtils.getConvertedValue(facesContext, component, (String) itemValue);
        }
        final String formattedValue = getFormattedValue(facesContext, (T) component, itemValue);
        final boolean contains;
        if (submittedValues == null) {
          contains = ArrayUtils.contains(values, itemValue);
        } else {
          contains = ArrayUtils.contains(submittedValues, formattedValue);
        }
        if (item.isNoSelectionOption() && component.isRequired() && values != null && values.length > 0 && !contains) {
          // skip the noSelectionOption if there is another value selected and required
          continue;
        }
        if (onlySelected != null) {
          if (onlySelected) {
            if (!contains) {
              continue;
            }
          } else {
            if (contains) {
              continue;
            }
          }
        }
        writer.startElement(HtmlElements.OPTION);
        writer.writeAttribute(HtmlAttributes.VALUE, formattedValue, true);
        if (item instanceof org.apache.myfaces.tobago.model.SelectItem) {
          final String image = ((org.apache.myfaces.tobago.model.SelectItem) item).getImage();
          if (image != null) {
            final AbstractUIStyle style = (AbstractUIStyle) facesContext.getApplication()
                .createComponent(facesContext, Tags.style.componentType(), RendererTypes.Style.name());
            style.setTransient(true);
            style.setBackgroundImage(image);
            style.setSelector(
                StyleRenderUtils.encodeIdSelector(component.getClientId(facesContext))
                    + " option[value=" + formattedValue + "]");
            // XXX This works not in common browsers...
            component.getChildren().add(style);
          }
        }
        Markup markup = item instanceof Visual ? ((Visual) item).getMarkup() : Markup.NULL;
        if (onlySelected == null && contains) {
          writer.writeAttribute(HtmlAttributes.SELECTED, true);
          markup = Markup.SELECTED.add(markup);
        }
        if (item.isDisabled()) {
          writer.writeAttribute(HtmlAttributes.DISABLED, true);
          markup = Markup.DISABLED.add(markup);
        }
        writer.writeClassAttribute(optionClass);

        final String label = item.getLabel();
        if (label != null) {
          writer.writeText(label);
        }
        writer.endElement(HtmlElements.OPTION);
      }
    }
  }

  protected String getFormattedValue(
      final FacesContext facesContext, final T component, final Object currentValue)
      throws ConverterException {

    if (currentValue == null) {
      return "";
    }

    final Converter converter = getConverter(facesContext, component, currentValue);
    if (converter != null) {
      return converter.getAsString(facesContext, component, currentValue);
    } else {
      return currentValue.toString();
    }
  }

  /**
   * May return null, if no converter can be find.
   */
  protected Converter getConverter(
      final FacesContext facesContext, final T component, final Object value) {

    Converter converter = null;
    if (component instanceof ValueHolder) {
      converter = ((ValueHolder) component).getConverter();
    }

    if (converter == null) {
      final ValueExpression valueExpression = component.getValueExpression("value");
      if (valueExpression != null) {
        Class converterType = null;
        try {
          converterType = valueExpression.getType(facesContext.getELContext());
        } catch (final Exception e) {
          // ignore, seems not to be possible, when EL is a function like #{bean.getName(item.id)}
        }
        if (converterType == null) {
          if (value != null) {
            converterType = value.getClass();
          }
        }
        if (converterType != null && converterType != Object.class) {
          converter = facesContext.getApplication().createConverter(converterType);
        }
      }
    }

    return converter;
  }
}
